To achieve permanent, intense colors with corresponding fastness properties, so-called oxidative dyes are used. Said dyes usually contain oxidative dye precursors, so-called developer components and coupler components. The developer components join together or couple with one or more coupler components to form, under the influence of oxidants or atmospheric oxygen, the actual dyes per se. Indeed, the oxidative dyes are exemplified by outstanding, long-lasting color results. To achieve natural-looking colors, however, a mixture from a larger number of oxidative dye precursors (ODP) must normally be used; in many cases, partially-oxidizing dyes are still used to create the tinting effect.
Most of the oxidative dyes used for stabilizing the dye precursors during storage and to accelerate the reaction during oxidative application have an alkali pH value, which is set with alkalizing agents such as alkanolamines, ammonia or inorganic bases.
To produce the dye, the alkali coloring component is usually mixed with a hydrous hydrogen peroxide solution to form a homogeneous creme or a homogeneous gel, and then applied immediately to the hair to be dyed. This dye mixture remains on the hair for a period of 5 to 60 minutes, until the oxidative formation of the dye on the hair is complete. The dye mixture is then washed out.
The aforementioned oxidative precursors (OPC) and alkalizing agents are usually worked into the hair in a cosmetically suitable carrier, such as a creme, for example. The carrier guarantees a homogeneous distribution and an adequate dwell time of the hair dye on the hair.